Grain-oriented magnetic steel sheet having no undercoat film comprising forsterite as primary component and having good magnetic characteristics

摘要

A grain oriented electromagnetic steel sheet is free from an undercoating mainly composed of forsterite (Mg₂SiO₄), excellent in processability and magnetic properties and useful to production cost, and has a composition containing, by % by mass, 2.0 to 8.0% of Si, wherein secondary recrystallized grains contains fine crystal grains having a grain diameter of 0.15 mm to 0.50 mm at a rate of 2 grains/cm² or more. In the process of producing the steel sheet, inhibitors are not utilized, and the fine crystal grains are achieved by high purification and low temperature final annealing.